25 
nothing in the published reports to indicate that the reporters took 
account of the fact that spent adults, about to die in the course 
of nature, are especially liable to infection, and that such cases of 
infection are worthless as evidence of the economic utility of the 
contagion method. We must further remember that chinch-bugs 
dying normally sometimes become covered with a post-mortem mold 
readily mistaken by the uncritical observer for the fungous para¬ 
site; and that even the freshly moulted adult has been more than 
once mistaken for the fungus-covered chincli-bug by experimenting 
farmers, misled by the white color of the insect just after it has 
•escaped from its pupal “crust.” 
These considerations, together with long practical experience of 
the unsatisfactory character of the statements of miscellaneous ob¬ 
servers, taken without selection, concerning difficult and unfamiliar 
matters of this description, lead me to attach but little value to 
this kind of evidence, for or against, and to look rather for the 
basis of a judgment on the economic bearing of this Kansas work 
to the descriptions of experiments by the laboratory assistants 
themselves. 
THE WORK IN ILLINOIS IN 1891-1894. 
Previous to 1891, my own experimental work on the insect 
diseases had been done almost wholly with bacterial forms, but in 
the spring of that year I began culture and infection experiments 
with Sporotrichum globuliferum, the fungus of white muscardine, 
and have continued now for four successive seasons to give par¬ 
ticular attention to this species from the economic standpoint. It 
has not been possible, however, with the funds and assistance at 
my disposal, to give the continuous attention of even one person 
to- this investigation, and the incomplete and sometimes doubtful 
character of many of our results is usually to be attributed to 
unavoidable interruptions of studies which should have been con¬ 
tinuous. We have endeavored to investigate, so far as possible, 
the spontaneous prevalence of white muscardine in the field; to 
determine the cheapest, best, and most convenient method and ap¬ 
paratus for the artificial culture of the muscardine fungus and 
of some other fungi of similar habit; to bring into comparison 
inoculation experiments in the laboratory and the field with spores de¬ 
rived from such artificial cultures and similar experiments with 
those coming directly from the dead insect itself; and to test the 
economic value of various methods for the increase and extension of 
this muscardine in the field, either as a preventive measure when 
chinch-bugs are relatively few, or as a means of arresting their 
ravages when they are excessively abundant and destructive. 
Spontaneous Occurrence. 
Notwithstanding the prevalent drouths of 1891, 1892, and 1893, 
and the consequent absence of any considerable outbreak of con¬ 
tagious disease among chincli-bugs, as well as the failure of all 
